全文获取类型
收费全文 | 490篇 |
免费 | 7篇 |
专业分类
化学 | 243篇 |
晶体学 | 3篇 |
力学 | 10篇 |
数学 | 62篇 |
物理学 | 179篇 |
出版年
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 20篇 |
2012年 | 18篇 |
2011年 | 15篇 |
2010年 | 9篇 |
2009年 | 10篇 |
2008年 | 25篇 |
2007年 | 22篇 |
2006年 | 20篇 |
2005年 | 16篇 |
2004年 | 20篇 |
2003年 | 8篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 14篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 8篇 |
1996年 | 14篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 13篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 12篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 13篇 |
1976年 | 3篇 |
1975年 | 7篇 |
1974年 | 11篇 |
1973年 | 5篇 |
1972年 | 5篇 |
1970年 | 4篇 |
1969年 | 3篇 |
1968年 | 6篇 |
1967年 | 6篇 |
1966年 | 5篇 |
1965年 | 3篇 |
排序方式: 共有497条查询结果,搜索用时 0 毫秒
491.
492.
Peter L. Bender 《General Relativity and Gravitation》2012,44(3):711-717
A paper published recently (Hogan et al. in Gen. Relativ. Gravit. 43:1953–2009, 2011) suggests the use of atom interferometry between satellites in Earth orbit to observe gravitational waves. The proposed altitude
and satellite separation are about 1,000 and 30 km respectively. The difference in acceleration between clouds of ultracold
atoms in atom interferometers near the two satellites would be detected by using laser beams between the interferometers.
Because of the measurement path being very short compared with the million km or longer measurement path for a proposed laser
interferometer gravitational wave antenna in space, the sensitivity to differential fluctuations in the laser phase as seen
by the atoms in the two atom interferometers is very high. Problems introduced by this high sensitivity to spurious laser
beam phase changes will be described in the first part of this paper. Then other limitations on the performance and on the
suggested types of sources that could be observed will be discussed. 相似文献
493.
494.
Norman L. Allinger Linrong Yang Ioan Motoc Charles Bender Jan K. Labanowski 《Heteroatom Chemistry》1992,3(1):69-72
The bond energy scheme for calculating heats of formation of organic molecules from ab initio data (6–31G*) has been extended to include 24 compounds containing sulfur in the sulfide oxidation state. The rms deviation from the experimental values for these compounds is 0.54 kcal/mol, which is approximately experimental error. 相似文献
495.
The crystal structures of several new alkali metal oxometallates are determined by single crystal XRD. 相似文献
496.
Anisotropic orientation states in materials such as liquid crystals, liquid crystalline polymers or polymeric electrets can be induced by the application of electric fields. This behaviour is exploited extensively in displays or sensors. Anisotropic optical properties induced by relatively high electric field strengths are used in the well known displays made from liquid crystalline materials. The anisotropy of electric properties in polymeric materials gives rise to properties such as the high piezoelectricity of fluorine containing electrets. Attempts have been made to investigate the orientational state induced by electric fields after poling using NMR techniques. However, there is only access to the irreversible part of the electrically induced orientation. In-situ application of (high) voltages during NMR experiments enables the investigation of the influence of the electric field on molecular orientational states or electrically-induced morphological changes. The NMR methods have been modified to investigate the dynamics of reorientation processes in electric fields and to extend the possible time range towards below1ms. The application of high voltages in NMR experiments requires experimental specifications. Some of our experiences are outlined in this paper. 相似文献
497.
Jessica L. Bender Robert M. Johnson Adam P. Smith Cassandra L. Fraser 《Macromolecular Symposia》2002,186(1):161-164
Polymeric metal complexes exhibiting useful properties were prepared by chelating macroligands to labile and inert metal ions. The specific structures elucidated through this method, as well as potential applications for these complexes are described. By carefully selecting the appropriate metal ion and polymer, these materials can be tuned for a host of applications in fields ranging from biomedicine to nanotechnology. 相似文献